tools/resolve_btfids: Install subcmd headers

Previously tools/lib/subcmd was added to the include path, switch to
installing the headers and then including from that directory. This
avoids dependencies on headers internal to tools/lib/subcmd. Add the
missing subcmd directory to the affected #include.

Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230124064324.672022-1-irogers@google.com

tools/bpf/resolve_btfids/Makefile

@@ -35,21 +35,29 @@ SUBCMD_SRC := $(srctree)/tools/lib/subcmd/
 BPFOBJ     := $(OUTPUT)/libbpf/libbpf.a
 LIBBPF_OUT := $(abspath $(dir $(BPFOBJ)))/
 SUBCMDOBJ  := $(OUTPUT)/libsubcmd/libsubcmd.a
+SUBCMD_OUT := $(abspath $(dir $(SUBCMDOBJ)))/
 
 LIBBPF_DESTDIR := $(LIBBPF_OUT)
 LIBBPF_INCLUDE := $(LIBBPF_DESTDIR)include
 
+SUBCMD_DESTDIR := $(SUBCMD_OUT)
+SUBCMD_INCLUDE := $(SUBCMD_DESTDIR)include
+
 BINARY     := $(OUTPUT)/resolve_btfids
 BINARY_IN  := $(BINARY)-in.o
 
 all: $(BINARY)
 
+prepare: $(BPFOBJ) $(SUBCMDOBJ)
+
 $(OUTPUT) $(OUTPUT)/libsubcmd $(LIBBPF_OUT):
 	$(call msg,MKDIR,,$@)
 	$(Q)mkdir -p $(@)
 
 $(SUBCMDOBJ): fixdep FORCE | $(OUTPUT)/libsubcmd
-	$(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
+	$(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(SUBCMD_OUT) \
+		    DESTDIR=$(SUBCMD_DESTDIR) prefix= \
+		    $(abspath $@) install_headers
 
 $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUT)
 	$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(LIBBPF_OUT)    \
@@ -63,7 +71,7 @@ CFLAGS += -g \
           -I$(srctree)/tools/include \
           -I$(srctree)/tools/include/uapi \
           -I$(LIBBPF_INCLUDE) \
-          -I$(SUBCMD_SRC) \
+          -I$(SUBCMD_INCLUDE) \
           $(LIBELF_FLAGS)
 
 LIBS = $(LIBELF_LIBS) -lz
@@ -71,7 +79,7 @@ LIBS = $(LIBELF_LIBS) -lz
 export srctree OUTPUT CFLAGS Q
 include $(srctree)/tools/build/Makefile.include
 
-$(BINARY_IN): $(BPFOBJ) fixdep FORCE | $(OUTPUT)
+$(BINARY_IN): fixdep FORCE prepare | $(OUTPUT)
 	$(Q)$(MAKE) $(build)=resolve_btfids
 
 $(BINARY): $(BPFOBJ) $(SUBCMDOBJ) $(BINARY_IN)
@@ -83,7 +91,8 @@ clean_objects := $(wildcard $(OUTPUT)/*.o                \
                             $(OUTPUT)/.*.o.d             \
                             $(LIBBPF_OUT)                \
                             $(LIBBPF_DESTDIR)            \
-                            $(OUTPUT)/libsubcmd          \
+                            $(SUBCMD_OUT)                \
+                            $(SUBCMD_DESTDIR)            \
                             $(OUTPUT)/resolve_btfids)
 
 ifneq ($(clean_objects),)
@@ -100,4 +109,4 @@ tags:
 
 FORCE:
 
-.PHONY: all FORCE clean tags
+.PHONY: all FORCE clean tags prepare

tools/bpf/resolve_btfids/main.c

@@ -75,7 +75,7 @@
 #include <linux/err.h>
 #include <bpf/btf.h>
 #include <bpf/libbpf.h>
-#include <parse-options.h>
+#include <subcmd/parse-options.h>
 
 #define BTF_IDS_SECTION	".BTF_ids"
 #define BTF_ID		"__BTF_ID__"